Project Summary A significant cause of mobility impairment in the elderly is peripheral arterial disease (PAD). PAD results in significant functional decline, reduced walking speed and distance, and lower physical activity levels, resulting in a loss of independence and impaired quality of life. The most effective therapy for PAD is rigorous exercise (e.g., walking). However, most PAD patients will not participate in supervised exercise, and walking-related pain provides a substantial barrier to unsupervised exercise, resulting in a lack of compliance. In addition, common comorbidities act as difficult-to-surmount barriers to rigorous physical exercise. Treadwell Corporation is pioneering an innovative treadling methodology and device (the TREDLRTM) to provide a therapy that can improve exercise tolerance in patients with PAD, accelerating their progress to reaping the functional benefits of more rigorous physical exercise. The TREDLRTM contains an internal flywheel that generates momentum while the user initiates repetitive ankle flexion and extension movements. Preliminary studies with the TREDLRTM prototype have demonstrated clear hemodynamic improvements in the lower extremities of participants who treadle. Additional pilot data from the collaborating sub-award PI, Dr. Jason Franz, have demonstrated in part that treadling affords the same ankle and calf muscle fascicle kinematics as walking without comparable levels of muscle activation ? a finding that we posit will translate to improved compliance and prolonged participation prior to onset of discomfort in people with PAD. We hypothesize that this will improve patients? functional exercise capacity and accelerate their progress to participation in more rigorous exercise therapy. In this Phase I STTR, the investigative team will evaluate this novel treadling methodology in individuals aged over 65 years with diagnosed PAD. To accomplish several early and critical milestones, this study will evaluate joint and muscle kinematic differences between treadling and conventional exercise (Aim 1), explore improvements in mobility and functional exercise capacity in individuals who treadle as compared to a control cohort (Aim 2), and assess user affect that may impact compliance and, ultimately, widespread adoption (Aim 3). Phase I is expected to demonstrate the feasibility of Treadwell?s proprietary treadling methodology as a method to improve exercise tolerance and mobility in older adults with PAD. These results will support further commercialization of the methodology and poise Treadwell to initiate rigorous multi-site clinical trials coupled with mechanistic outcomes in Phase II, which will be necessary to drive clinical acceptance of the methodology.